Telephone key



Oct. 29, 1946. L. B. HAIGH ET AL TEIZJEIPHONIE.'l KEY Filed May 6, 1944` 2 Sheets-Sheet 1 0d 29, 1946. L. HAIGH ErAL TELEPHONE KEY Filed May 6, 1944 2 Sheets-Sheet 2 e@ Se' INVENTORS LESLIE B. H/q/GH FHNKL//Y r4.

'Y `AGENT Patented Oct. 29, 1946 TELEPHONE KEY Leslie BL Haigh, West Orange, and Franklin A. Stearn, Westfield, N. J., assignors to Federal Telephone and Radio Corporation, New York,

N. Y., a corporation ofy Delaware Application May 6, 1944, Serial No. 534,420

2 Claims. 1

Thisinvention relates to electrical switching keys vof the type known as lever keys and more particularly to such keys designed for use in-places where space is at a premium.

One object of this invention is to provide a lever key which willbe easy to manufacture and which will require the minimum number of parts in manufacturing.

Another object of this invention is to provide a key in which the frame and actuating cam assembly is held together by means of a single screw, this screw likewise Vmountingfthe spring assembly or assemblies-upon the frame-proper of the key.

Yet another object of this invention is to pro vide a key in which only a singletype of cam is employed whether the key be a two or afthreev yposition key and whether locking or non-locking action be required, and infwhich pairs of oppositely disposedv holesare provided in theV key frame, in which holes a stop pin or pins may alternatively be placed to determine the extent of rotation of thel cam and thevextent ofA throw of the key.

Another purpose of this invention is to provide a key in which economical-assembly is promoted by arranging the cam rollers so that theyl run freely upon the cam stud and are held'thereupon by a portion of the frame.

Other purposes and advantagesof this invention will be apparent to those skilled in the artv from a consideration of the drawings hereunto appended, where Fig. 1 represents a single sided key, in front elevation and unoperated position.

Fig. 2 represents a single sided key, in front elevation and in operated position.

Fig. 3 shows the same key in side elevation and unoperated position.

Fig. 4 shows, in rear elevation, unoperated position.

Fig. 5 is a top plan view of the vsame key.

Fig. 6 is a front elevation, of a double sided key according to this invention, shown in un'- operated position.

Fig. 7 is a front elevation of in operated position.

Fig. 8 is a side elevation of a double sided key, in unoperated position; and

Fig. 9 is a side view of the cam employed in this key.

a double sided key the same key inv las, fastened upon the sides thereof by meansof screws I5, two spring assemblies I6 and I .'I, locateduponthe opposite sides of member I4. The number of contact springs forming each of thesetwo assemblies and their interconnection and operation with respect to opening and closingvarious contacts, is not material to this linvention, sincethe number of springs used and these various interrelationships can be determined according tothe particular use `to which the key is `to be put.

More rigid members I8 and I 9 Vmay be provided in order to limit the motion of certain springs,

if so desired. The actuation of the springsy uponv the respective sides of member I4is brought about by actuating contact springs 20 and 2 I, which are elongated above the ends of the other contactY springs and have the elongated lportions thereof formed in such fashion that roller 22 will cause lateralmotions of the actuating springs. Roller 22 rotates freely upon cam stud 23, and stud 23 isr mounted upon a portion of the cam body 24, which latter is provided with a suitable handle 25. roller 22 is prevented from running off the end of the stud by means of a lip 26 which projects downwardly from the upper portion of frame member I0. This avoids the'necessity of riveting a washer upon the stud after the roller has been placed thereupon, or otherwise retaining the roller in position thereupon.

Frame members I0 and II are provided with oppositely located bearing apertures 36. Cam body 24 is provided with a bearing 50, of the hollow shaft type, which rotates upon a piny 30. This pin has the two ends'thereof inserted into the pair of corresponding apertures 39', atV the time when the key is assembled. Frame members l0 and II are also provided with suitable apertures 29 and 29'; registering with one another when the respective frame members are as- The is secured by a square nut I2'- which sits in a recess inmember I4. Member I4 Single non-lock Single lock Double non-lock Double lock Lock on one side, non-lock on the other side.

If the key is to be locking on either side, no pin 54 is used on that side the motion of the cam being limited only by the yprojection 52. In this extreme position the tension of the spring 20 or 2| is exerted against the roller 22 in such direction that it holds the cam in its operating posi-- tion by a toggle action. A pin in the pair of upper holes on either side' makes it non-locking on that side since the force applied by the spring against the roller is in such a direction that it will return the cam to its medial position when the key is released. A pin in the pair of lower holes on either side blocks the cam against rotation on that side and converts the key into a twoposition or single key.

One form of stop pin is indicated at 54 in the drawings, and is preferably identical with pin 3D.

Referring now to the double sided form of key shown in Figs. 6, 7 and 8, the frame is here constituted by two substantially identical members 40 and 4|. Spring assemblies are arranged upon both sides of these frame members, the members being held together by screw |2', which passes also through the mounting members I4 of both spring assemblies. In this case, also, this allows the employment of a single screw to hold the frame members together and the spring assemblies thereto, thus saving time in assembly and reducing the cost of manufacture.

The number of springs and the arrangements of contacts employed in this form of key are not essential features of the instant invention and may be selected according to the desired functioning of the key. The members serving to actuate the contact springs are similar to those previously shown and described in connection with the single sided form of key and here bear corresponding reference numerals.

In the double sided key, each frame member 40 and 4| is provided with its own fastening apertures located upon the extreme upper surface thereof, into which apertures fastening screws 42 and 43 may be threaded.

The alignment of the two frame members is maintained by studs I3 one pressed out of or secured in each frame member. Oppositely disposed pairs of apertures 29' are provided in the upper portion of frame members 40 and 4|, so that the pins 54 used as stops for the cam may have their positions suitably determined at the time of assembly, according to the particular function which the key is to perform. Accordingly the double sided key may likewise be utilized in any one of the five possible operative combinations, as above detailed in describing the single sided key.

In the double sided key, there are provided two cam studs 23', located upon opposite sides of the cam body 24 and each stud bears a cam roller 22'. In this case, likewise, a suitable lip 26 extends downwardly from the upper portion of each frame member 4D and 4|, so that the cam rollers are prevented from running oi the ends of the respective studs upon which they rotate.

In both the single and double sided forms of key according to this invention, the extreme angular rotation of the cam may be limited by suitable means, which do not form an essential part of the instant invention. For example, the lower portion of the cam may be provided with one or more projections, 5| in the single key and 5| in the double key, which encounter a limiting or stop projection 52 or 52', provided upon one or both of the frame members in the two forms of key.

Fig. 9 shows the cam provided with main stop projections 5| and ancillary stop projections 55, these latter being located at a shorter distance from the axis of rotation of the cam than are projections 5|. This arrangement permits the uppermost apertures to be located at a suflicient distance from the top of the key to enable insertion of the mounting screws 42, 43 without fouling the stop pin when it is inserted in these apertures. According to the particular pair of apertures 29 or 29 chosen, stop pin 54 will encounter one only of the stop projections 5| or 55, thus allowing the degree of angular rotation of the cam to be determined by such selected position for the stop pin, since the respective radii of the various pairs of apertures with respect to the axis of rotation oi the cam are not identical but are Varied so that the desired cam projection may be engaged with the stop pin.

Modifications and alterations of the keys above described by way of example, will be apparent to those skilled in the art and this invention is limited only by the scope of the hereunto appended claims.

What is claimed is:

1. A switching key comprising a frame, a rotatable cam mounted upon a pivot in said frame, Contact springs operable by said cam, a projection on the periphery of said cam, a plurality of pairs of oppositely disposed holes in said frame. said pairs of holes being located at different angular positions relative to the said pivot and at such radial distance from said pivot that said cam projection passes over each of said pairs of holes during rotation of said cam and a removable pin for insertion in any one of said pairs of holes for cooperation with said projection whereby the degree of rotation of said cam and the extent of throw of the key may be varied.

2. A switching key comprising a frame, a rotatable cam mounted upon a pivot in said frame, contact springs operable by said cam, a plurality of projections on the periphery of said cam having cam surfaces at different radial distances from said pivot, a plurality of pairs of oppositely disposed holes in said frame, said pairs of holes being located at different radial distances from said pivot such that said projections each pass 5 over one of said pairs of holes during rotation of said cam and a removable pin for insertion in any one of said pairs of holes for cooperation with said projections whereby the degree of rotation of said cam and the extent of throw of the key may be varied.

LESLIE B. HAIGH. FRANKLIN A. STEARN. 

